MoO₂@C modified separator as an interlayer for high performance lithium-sulfur batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical energy density but face challenges like polysulfide shuttling and low conductivity.
• Commercialization of Li-S batteries is hindered by issues impacting cycle life and efficiency.

Purpose of the Study:

• To investigate the efficacy of a molybdenum dioxide coated with carbon composite (MoO2@C) as a separator coating for Li-S batteries.
• To enhance the electrochemical performance and stability of Li-S cells by mitigating active material loss.

Main Methods:

• Synthesized MoO2@C nanoparticles via hydrothermal method and high-temperature calcination.
• Coated the synthesized MoO2@C onto a separator using acetylene black.
• Evaluated the electrochemical performance of the modified Li-S cells.

Main Results:

• The MoO2@C coating demonstrated a synergistic effect of physical barrier and chemical adsorption, reducing active substance loss.
• Modified Li-S cells exhibited improved electrochemical performance, with a high initial discharge specific capacity of 917 mA h g⁻¹ at 1.0 A g⁻¹.
• Excellent cycling stability was observed, retaining 618 mA h g⁻¹ after 300 cycles at 1.0 A g⁻¹ and 551 mA h g⁻¹ after 200 cycles at 2.0 A g⁻¹.

Conclusions:

• The MoO2@C coated separator effectively enhances the performance of lithium-sulfur batteries.
• This approach offers a promising strategy for developing stable and high-performance next-generation energy storage systems.